{"product_id":"sierra-18-3221-water-tube-for-mercruiser-gen-ii-sterndrives-replaces-oem-32-814384-32-860220","title":"Sierra Water Tube Guide 18-3221, Replaces 23-816583, for MerCruiser Gen II","description":"\u003cp\u003eThe Sierra 18-3221 Water Tube Guide is a cooling system component engineered for MerCruiser Gen II sterndrive applications. It directs cooling water flow through the drive unit as part of the raw water circulation path, and is molded from durable white polypropylene (PP) for resistance to corrosion and degradation in the marine cooling environment. With a compact outside diameter of 1.49 inches, an item length of 1.25 inches, and a nominal wall thickness of 0.12 inches, this water tube guide is sized to fit precisely in place of the original equipment part it replaces.\u003c\/p\u003e\u003cp\u003eAs a direct-fit replacement, the Sierra 18-3221 cross-references to OEM part number 23-816583, letting owners restore proper cooling water flow without sourcing an original equipment part. It is built to Sierra's quality standard for MerCruiser Gen II cooling system service, making it a straightforward maintenance or repair item when a water tube guide has cracked, degraded, or is being replaced as part of a broader cooling system overhaul.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-3221\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Water Tube Guide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Polypropylene (PP)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 1.49 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Length:\u003c\/strong\u003e 1.25 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal Wall Thickness:\u003c\/strong\u003e 0.12 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.04 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282243876\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFitment:\u003c\/strong\u003e MerCruiser Gen II\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 23-816583\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFor MerCruiser Gen II sterndrive units.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cp\u003e23-816583\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-3221 Water Tube Guide fit?\u003c\/strong\u003e The Sierra 18-3221 is designed for MerCruiser Gen II sterndrive applications, where it guides cooling water flow through the drive unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does 18-3221 replace?\u003c\/strong\u003e Sierra 18-3221 replaces OEM part number 23-816583, so it can be installed as a direct substitute for that original equipment water tube guide.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the water tube guide made from?\u003c\/strong\u003e It is molded from white polypropylene (PP), a plastic chosen for its resistance to corrosion and degradation in a marine cooling water environment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow big is the Sierra 18-3221 Water Tube Guide?\u003c\/strong\u003e It has an outside diameter of 1.49 inches, an item length of 1.25 inches, and a nominal wall thickness of 0.12 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does part 18-3221 weigh?\u003c\/strong\u003e The Sierra 18-3221 Water Tube Guide weighs 0.04 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3221 a genuine OEM part or an aftermarket replacement?\u003c\/strong\u003e It is a Sierra-branded aftermarket replacement part manufactured to match the fit and function of OEM part 23-816583.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this water tube guide fit a MerCruiser Gen I drive?\u003c\/strong\u003e The Sierra 18-3221 is specified for MerCruiser Gen II applications; fitment for other drive generations is not listed for this part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-3221 Water Tube Guide?\u003c\/strong\u003e The UPC for the Sierra 18-3221 Water Tube Guide is 808282243876.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace the water tube guide in the cooling system?\u003c\/strong\u003e A cracked, worn, or degraded water tube guide can disrupt raw water flow through the MerCruiser Gen II drive, so replacing it with the Sierra 18-3221 restores proper cooling water circulation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-3221 come as a single piece?\u003c\/strong\u003e Yes, the Sierra 18-3221 Water Tube Guide is supplied as a single unit count item.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988141682907,"sku":"SIE-18-3221","price":13.91,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-3221_lg__04141.1558124493.500.750.jpg?v=1785188105","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-3221-water-tube-for-mercruiser-gen-ii-sterndrives-replaces-oem-32-814384-32-860220","provider":"Good Vibes Marina","version":"1.0","type":"link"}